Dr Boesen has received financial support for the current PhD project from Novartis, Teva, and Sanofi Genzyme; served on the scientific advisory board for Teva; received honoraria for lecturing from Novartis; and received support for congress participation from Teva. Dr Blinkenberg has served on scientific advisory boards for Biogen Idec, Merck Serono, Novartis, Sanofi-Aventis, and Teva; received speaker honoraria from Biogen Idec, Merck Serono, BayerSchering, Novartis, Teva, Roche, and Sanofi-Aventis; received consulting honoraria from the Danish Multiple Sclerosis Society, Biogen Idec, and Merck Serono; and received funding for travel from Biogen Idec, Merck Serono, Sanofi-Aventis, and Sanofi Genzyme. Dr Sørensen has received personal compensation for serving on scientific advisory boards, steering committees, or independent data monitoring boards for Biogen, Merck, Novartis, Teva, GlaxoSmithKline, medDay Pharmaceuticals, Sanofi Genzyme, Celgene, and Forward Pharma; and has received speaker honoraria from Biogen, Merck, Teva, Sanofi Genzyme, and Novartis; his department has also received research support from Biogen, Merck, TEVA, Novartis, Sanofi-Aventis/Genzyme, RoFAR, and Roche. Dr Magyari has served on the scientific advisory board for Biogen Idec, Novartis, and Merck Serono; has received honoraria for lecturing from Biogen Idec, Merck Serono, Novartis, and Sanofi Genzyme; and has received support for congress participation from Biogen Idec, Novartis, Genzyme, and Teva. Dr Erdal has declared no conflicts of interest.

INTRODUCTION

Multiple sclerosis (MS) with onset before the age of 18 years is characterised by higher relapse rates and more severe MRI evidence of inflammation compared to adult-onset MS. Only persons older than 18 years have been included in randomised placebo-controlled trials; however, previous observational studies have shown that early initiation of disease-modifying therapy (DMT) may be beneficial for children with MS. No official international treatment guidelines are available for paediatric-onset MS (POMS), and there is limited evidence of DMT in children with MS.

AIMS

The aim of this study was to describe DMT in POMS in Denmark from 1996, when DMT became available, until data were sourced in May 2017.

METHOD

We conducted a nationwide population-based cohort study using prospectively collected real-world data derived from the Danish Multiple Sclerosis Registry. We identified a cohort of 195 children diagnosed with MS before 18 years of age. Since recording of all patients treated with DMT is mandatory in Denmark, the cohort is considered effectively complete.

RESULTS

Out of 195 patients, 123 (63%) started DMT before turning 18 years of age. The group of treated patients had a mean age at diagnosis of 14.9 years and a mean age at treatment initiation of 15.9 years (median: 16 years; range: 4–17 years). Most of the children received a first-line DMT, with IFN-β being the most common choice (85%). IFN-β1a administered subcutaneously was the most commonly used treatment from 1996–2005 (53%), while IFN-β1a administered intramuscularly was more common from 2006–2015 (59%). From 2011–2015, only 1 (2%) patient started treatment with dimethyl fumarate and 5 (9%) patients with teriflunomide. Two patients received induction therapy with mitoxantrone (in 2005). Natalizumab was the only second-line agent used as a primary treatment and was given to 6 children after 2011.

During the 20 years follow-up, a total of 107 (87%) children switched DMT or discontinued treatment, either due to adverse events or disease breakthrough. Of the 123 treated POMS cases, 39 children (32%) received >1 DMT before turning 18 years of age. The mean number of DMT per child, initiated before the age of 18 years, was 1.4. Natalizumab and fingolimod were used as second-line DMT in 18 out of 39 subjects. Fingolimod was prescribed more frequently than natalizumab when escalation of therapy was indicated, and three patients switched from natalizumab to fingolimod. IFN were used in 10 children (26%) after the first switch.

CONCLUSION

In conclusion, this study based on real-world data provides an insight into the patterns of use of DMT in POMS in Danish clinics.